Nothing past calc I I’d reckon. I think one of the issues was how function calls can seem arbitrary at first (esp in python). You have imported functions, user defined functions, built in functions, etc. so when students see a function call, they aren’t confident in knowing where it came from, causing distress.

Most students really dislike anything that appears arbitrary which I think plays into this. One pre-med student I knew despised math after being taught 0!=1 because it seemed seemed completely made up to him and broke established rules.

Part of the onus falls on instructor to clear up areas like this (e.g. explain the cardinality of the set containing just the empty set is 1, 0!=1 allows for many formulas to be expressed tersely, etc). The other component of this is that the students who dislike ambiguity self select out of the program.